1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2000-2010
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 *
6 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Andreas Heppel <aheppel@sysgo.de>
8 */
9
10 #include <common.h>
11 #include <command.h>
12 #include <env.h>
13 #include <env_internal.h>
14 #include <sort.h>
15 #include <linux/stddef.h>
16 #include <search.h>
17 #include <errno.h>
18 #include <malloc.h>
19 #include <u-boot/crc.h>
20
21 DECLARE_GLOBAL_DATA_PTR;
22
23 /************************************************************************
24 * Default settings to be used when no valid environment is found
25 */
26 #include <env_default.h>
27
28 struct hsearch_data env_htab = {
29 .change_ok = env_flags_validate,
30 };
31
32 /*
33 * Read an environment variable as a boolean
34 * Return -1 if variable does not exist (default to true)
35 */
env_get_yesno(const char * var)36 int env_get_yesno(const char *var)
37 {
38 char *s = env_get(var);
39
40 if (s == NULL)
41 return -1;
42 return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
43 1 : 0;
44 }
45
46 /*
47 * Look up the variable from the default environment
48 */
env_get_default(const char * name)49 char *env_get_default(const char *name)
50 {
51 char *ret_val;
52 unsigned long really_valid = gd->env_valid;
53 unsigned long real_gd_flags = gd->flags;
54
55 /* Pretend that the image is bad. */
56 gd->flags &= ~GD_FLG_ENV_READY;
57 gd->env_valid = ENV_INVALID;
58 ret_val = env_get(name);
59 gd->env_valid = really_valid;
60 gd->flags = real_gd_flags;
61 return ret_val;
62 }
63
env_set_default(const char * s,int flags)64 void env_set_default(const char *s, int flags)
65 {
66 if (sizeof(default_environment) > ENV_SIZE) {
67 puts("*** Error - default environment is too large\n\n");
68 return;
69 }
70
71 if (s) {
72 if ((flags & H_INTERACTIVE) == 0) {
73 printf("*** Warning - %s, "
74 "using default environment\n\n", s);
75 } else {
76 puts(s);
77 }
78 } else {
79 debug("Using default environment\n");
80 }
81
82 if (himport_r(&env_htab, (char *)default_environment,
83 sizeof(default_environment), '\0', flags, 0,
84 0, NULL) == 0)
85 pr_err("## Error: Environment import failed: errno = %d\n",
86 errno);
87
88 gd->flags |= GD_FLG_ENV_READY;
89 gd->flags |= GD_FLG_ENV_DEFAULT;
90 }
91
92
93 /* [re]set individual variables to their value in the default environment */
env_set_default_vars(int nvars,char * const vars[],int flags)94 int env_set_default_vars(int nvars, char * const vars[], int flags)
95 {
96 /*
97 * Special use-case: import from default environment
98 * (and use \0 as a separator)
99 */
100 flags |= H_NOCLEAR;
101 return himport_r(&env_htab, (const char *)default_environment,
102 sizeof(default_environment), '\0',
103 flags, 0, nvars, vars);
104 }
105
106 /*
107 * Check if CRC is valid and (if yes) import the environment.
108 * Note that "buf" may or may not be aligned.
109 */
env_import(const char * buf,int check)110 int env_import(const char *buf, int check)
111 {
112 env_t *ep = (env_t *)buf;
113
114 if (check) {
115 uint32_t crc;
116
117 memcpy(&crc, &ep->crc, sizeof(crc));
118
119 if (crc32(0, ep->data, ENV_SIZE) != crc) {
120 env_set_default("bad CRC", 0);
121 return -ENOMSG; /* needed for env_load() */
122 }
123 }
124
125 if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
126 0, NULL)) {
127 gd->flags |= GD_FLG_ENV_READY;
128 return 0;
129 }
130
131 pr_err("Cannot import environment: errno = %d\n", errno);
132
133 env_set_default("import failed", 0);
134
135 return -EIO;
136 }
137
138 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
139 static unsigned char env_flags;
140
env_import_redund(const char * buf1,int buf1_read_fail,const char * buf2,int buf2_read_fail)141 int env_import_redund(const char *buf1, int buf1_read_fail,
142 const char *buf2, int buf2_read_fail)
143 {
144 int crc1_ok, crc2_ok;
145 env_t *ep, *tmp_env1, *tmp_env2;
146
147 tmp_env1 = (env_t *)buf1;
148 tmp_env2 = (env_t *)buf2;
149
150 if (buf1_read_fail && buf2_read_fail) {
151 puts("*** Error - No Valid Environment Area found\n");
152 } else if (buf1_read_fail || buf2_read_fail) {
153 puts("*** Warning - some problems detected ");
154 puts("reading environment; recovered successfully\n");
155 }
156
157 if (buf1_read_fail && buf2_read_fail) {
158 env_set_default("bad env area", 0);
159 return -EIO;
160 } else if (!buf1_read_fail && buf2_read_fail) {
161 gd->env_valid = ENV_VALID;
162 return env_import((char *)tmp_env1, 1);
163 } else if (buf1_read_fail && !buf2_read_fail) {
164 gd->env_valid = ENV_REDUND;
165 return env_import((char *)tmp_env2, 1);
166 }
167
168 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
169 tmp_env1->crc;
170 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
171 tmp_env2->crc;
172
173 if (!crc1_ok && !crc2_ok) {
174 env_set_default("bad CRC", 0);
175 return -ENOMSG; /* needed for env_load() */
176 } else if (crc1_ok && !crc2_ok) {
177 gd->env_valid = ENV_VALID;
178 } else if (!crc1_ok && crc2_ok) {
179 gd->env_valid = ENV_REDUND;
180 } else {
181 /* both ok - check serial */
182 if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
183 gd->env_valid = ENV_REDUND;
184 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
185 gd->env_valid = ENV_VALID;
186 else if (tmp_env1->flags > tmp_env2->flags)
187 gd->env_valid = ENV_VALID;
188 else if (tmp_env2->flags > tmp_env1->flags)
189 gd->env_valid = ENV_REDUND;
190 else /* flags are equal - almost impossible */
191 gd->env_valid = ENV_VALID;
192 }
193
194 if (gd->env_valid == ENV_VALID)
195 ep = tmp_env1;
196 else
197 ep = tmp_env2;
198
199 env_flags = ep->flags;
200 return env_import((char *)ep, 0);
201 }
202 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
203
204 /* Export the environment and generate CRC for it. */
env_export(env_t * env_out)205 int env_export(env_t *env_out)
206 {
207 char *res;
208 ssize_t len;
209
210 res = (char *)env_out->data;
211 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
212 if (len < 0) {
213 pr_err("Cannot export environment: errno = %d\n", errno);
214 return 1;
215 }
216
217 env_out->crc = crc32(0, env_out->data, ENV_SIZE);
218
219 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
220 env_out->flags = ++env_flags; /* increase the serial */
221 #endif
222
223 return 0;
224 }
225
env_relocate(void)226 void env_relocate(void)
227 {
228 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
229 env_reloc();
230 env_fix_drivers();
231 env_htab.change_ok += gd->reloc_off;
232 #endif
233 if (gd->env_valid == ENV_INVALID) {
234 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
235 /* Environment not changable */
236 env_set_default(NULL, 0);
237 #else
238 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
239 env_set_default("bad CRC", 0);
240 #endif
241 } else {
242 env_load();
243 }
244 }
245
246 #ifdef CONFIG_AUTO_COMPLETE
env_complete(char * var,int maxv,char * cmdv[],int bufsz,char * buf,bool dollar_comp)247 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf,
248 bool dollar_comp)
249 {
250 struct env_entry *match;
251 int found, idx;
252
253 if (dollar_comp) {
254 /*
255 * When doing $ completion, the first character should
256 * obviously be a '$'.
257 */
258 if (var[0] != '$')
259 return 0;
260
261 var++;
262
263 /*
264 * The second one, if present, should be a '{', as some
265 * configuration of the u-boot shell expand ${var} but not
266 * $var.
267 */
268 if (var[0] == '{')
269 var++;
270 else if (var[0] != '\0')
271 return 0;
272 }
273
274 idx = 0;
275 found = 0;
276 cmdv[0] = NULL;
277
278
279 while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
280 int vallen = strlen(match->key) + 1;
281
282 if (found >= maxv - 2 ||
283 bufsz < vallen + (dollar_comp ? 3 : 0))
284 break;
285
286 cmdv[found++] = buf;
287
288 /* Add the '${' prefix to each var when doing $ completion. */
289 if (dollar_comp) {
290 strcpy(buf, "${");
291 buf += 2;
292 bufsz -= 3;
293 }
294
295 memcpy(buf, match->key, vallen);
296 buf += vallen;
297 bufsz -= vallen;
298
299 if (dollar_comp) {
300 /*
301 * This one is a bit odd: vallen already contains the
302 * '\0' character but we need to add the '}' suffix,
303 * hence the buf - 1 here. strcpy() will add the '\0'
304 * character just after '}'. buf is then incremented
305 * to account for the extra '}' we just added.
306 */
307 strcpy(buf - 1, "}");
308 buf++;
309 }
310 }
311
312 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
313
314 if (idx)
315 cmdv[found++] = dollar_comp ? "${...}" : "...";
316
317 cmdv[found] = NULL;
318 return found;
319 }
320 #endif
321